Improvement in cut-off-valve gear for steam-engines



NITED STATES PATENT MQililrcn.

WELLS L. COLBORN, OF ELMIRA, NEW YORK, ASSIGNOR TO HIMSELF AND JOHN M. D. GREENE.

IMPROVEMENT IN CUT-OFF-VALVE GEAR FOR. STEAM-ENGHNES.

Specification forming part of Letters Patent No. 41,810, dated March l, 1864.

To all whom it may concern:

Be it known that I, WELLS L. UOLBORN, of Elmira, in the county of Ohemung and State of New York, have invented a new and useful Improvement in Variable Apparatus for OperatingOut-Oltl Valves of Steam-Engines; and I do hereby declare that the following is a full and exact description thereof, reference being had to the. accompanying drawings, making part of this specification.

Figure l is al central longitudinal vertical section of my improved device, the parts for operating the valve being shown in elevation; Fig. k2, an end elevation thereof; Fig. 3, a transverse vertical section of the valve and case in the plane of line w Fig. l; Fig. 4, a perspective view of the operating parts detached 5 Fig. 5, an elevation of the rock-lever and slide that operate the valve; Fig. 6, a transverse horizontal section of the operating parts in plane of line y y, Fig. l. y

Likeletters of referenceindicate corresponding parts in all the figures.

The object of my invention is to regulate the flow of steam from the steam-pipe to the steam-chest, so as to equalize action, whether the pressure be greater or less. y

As represented-n the drawings, Ais avalvecase, whose induction-opening a receives the steam from the steam-pipe, and whose eduction-outlet b discharges it into the steam-chest, whenceitpasses to thepiston-cylinder,through the ordinary slide-valves. In this case A are situated two cylinders, B and U, which form the valve proper, the outer one being stationary and having a steam-chamber, c, around it, and the inner one turning with a shaft, D, and tting closely within the outer. Both cylinders are provided with ports through which the steam enters, six being represented in each in the drawings, and these are so relatively arranged that those of the inner cylinder pass those of the outer at each direct and reverse stroke, whether said stroke is long or short. The regulation of the flow of steam is accomplished not by the length of stroke or extent of movement of the inner cylinder, but by the quickness or slowness of the stroke, whereby the ports are a less or greater timein passing each other.

The shaft D extends through both ends of the case, being adjusted, if desired, at the rear extremity by means of a screw-thread and nut, while with the opposite extremity is connected the variable apparatus by which the valve is operated, and in which my invention consists. To the end ot' the shaft is rigidly secured a crank, E, of suitable length, having at its bottom a pivot-joint, d, which connects with a rock-lever, G, actuated by means of a rod, H, at the opposite end, that receives motion from the eccentric of the engine. This rock-lever is provided with a slot, f, or equivalent, of suitable length, in which adjusts up and down a fulerum-slide, g, connected with and turning freely on a wrist, h, Fig. 6, connecting in a similar manner withY a sliding block, I. This block I slides up and down in suitable heads or guides, K K, at the proper position in front ot' the case, and is operated by means of a rod, L, which connects it in any suitable manner with the ordinary governor or regulator above. The operation of the deviceA is obvious from the description already given. As the governorballs rise or fall, the rod L, the sliding block I,`

and consequently the t'ulcrum-slide g rise or fall in a corresponding degree, as indicated by the red lines, Figs. 2 and 5. The slide g forms the fuler'um on which the rock-lever G turns, and as the upper and lower arms are lengthenedror shortened it is apparent the motion of the shaft D and valve-cylinder C is corof the cylinder is the slowest, so as to give,

the greatest time for the passage of the steam.

This arrangement is very simple and not liable to get out of order, and is very effective in accomplishing the object for which it is designed. The valve is nearly balanced by the pressure of the steam all around it, and therefore but very little force is necessary in operating it. By regulating the flow of the steam by a variation in the motion of the valve instead of by opening :L greater or less space otl the ports silnpiy,1;he action is much more regular, there is less jor and strain to the mnchinery, and a great saving in the expense of' running an engine.

I do notl intend to limit myself to the combination with the particular kind of vulve shown in the drmvings,es itis evident that it is applicable to many kinds of' valves used for this purpose.

1 claim- Regulating the flow of steam by means ot' i the adjusting sliding` block I, connected with the governor7 the fuicruinslde g, rocklever Gr, provided with slotf, or equivalent, and connected with the eccentric and the crank E, the Whole arranged substantially as described.

In witness whereof I have hereunto signed my name in the presence of two subscribing,`

witnesses. A

WELLS L. COLBORN. Witnesses:

J. FRAsER, R. F. OsGooD. 

